The tone was sneering, accusing, combative. "Sounds to me like you're finding this all a bit of a turn-on, Sean. Why are the British press incapable of waiting until trouble actually happens before reporting on it?" Due to the wonders of Bluetooth, I had just blogged from Stuttgart's Koenigstrasse, warning of impending violence between the England and German fans at the World Cup, yet immediately I was accused of being some sort of sick hooligan voyeur.

My initial reaction was an overwhelming desire to hunt down the poster and administer a sharp, swift rejoinder. Instead I bit my tongue, registered to post on Guardian Unlimited's World Cup blog, and politely responded. Having followed England from Frankfurt to Nuremburg to Cologne, I knew their yobbish fans' modus operandi: the marking of territory with St George flags, followed by hours of drunken taunts to police and passers-by, who always ignored rather than confronted. But, as I pointed out, this time was different. Twenty metres from me, hundreds of bare-chested England fans were singing Ten German Bombers, the theme from Dambusters, Two World Wars and One World Cup on loop, like choralists at Last Night of the Chavs - right next to a huge swell of German youths, who stood in front of them like a rugby team accepting the challenge of the Haka. It was a riot waiting to happen.

An hour or two after my initial post, it kicked off. The skirmishes, thankfully, were fairly minor, although several hundred England fans were arrested for disorderly behaviour later that evening. But what interested me more was the discussion that followed on the blog. Every time I clicked "refresh" there was a different take on the England supporters' behaviour in Germany or the media reaction to it. It made for compelling reading. Several of the most thoughtful points came, intriguingly, from my initial accuser.

We're hoping for a similar level of debate now that we've launched a sport blog, which combines the best writing from Guardian Unlimited, Guardian and Observer sport. There's certainly a market for such a blog. During World Cup month, we had over 25,000 comments posted and four million page impressions. The challenge now is to ensure the level of debate doesn't descend into the equivalent of a messy 4am nightclub brawl, with screams and not much else.

That's not easy, of course. Posters are anonymous, while a writer can easily be publicly shot at. What's more, it's often human nature to respond to something that irks and irritates, rather than an article a reader agrees with. During the World Cup, for instance, those writers who donned the journalistic equivalent of pom-poms and a ra-ra skirt in support of England were generally lauded, while those who pointed out the deficiencies in Sven-Goran Eriksson's team were wildly harangued. One writer, who in the aftermath of England's defeat to Portugal stuck up for Cristiano Ronaldo, was attacked with a blitzkreig of abusive posts and one death threat.

It shouldn't be like this. Many of our contributors are lucid, intelligent and thoughtful, and so are our writers. We all should be beyond petty nationalism and name-calling. Introducing 24-hour monitoring of the blog, as we will do from early next month, should dissuade the shouters. But we also realise that, as journalists, we must contribute too: we can't just write our piece and slink off once the conversation starts. We need to become part of the community.

On Guardian Unlimited Sport, we have a stronger community than most, largely thanks to our massively successful over-by-over reports on cricket, as well as our popular emails the Fiver and the Spin. We hope to make the sport blog just as successful.